巻号一覧
54 巻 (1998)
- 4 号 p. 315-
- 3 号 p. 225-
- 2 号 p. 125-
- 1 号 p. 1-
54 巻, 2 号
選択された号の論文の9件中1～9を表示しています
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岩本 彰, 浦野 慎一, 新垣 雅裕1998 年 54 巻 2 号 p. 125-131
発行日: 1998/06/15
公開日: 2010/02/25
ジャーナル フリーThe analysis of the meteorological data and soil moisture observed in the cool-dry season at the Zambezi river flood plain and Mongu meteorological station shows that water supply from groundwater covers almost two-third of the actual evapotranspiration rate in the objective development area and amounted to 1mm/d.
The potential evapotranspiration rates in this area after the development as paddy field were estimated at more than 6mm/d for hot-dry season. These rates can be considered as a proper rate, because in this area there is a lot of fair or partly cloudy days with low humidity in hot-dry season. It was found that net radiation had direct effect upon the evapotranspiration rate. So if it is needed to get more accurate rate for paddy field, the estimation of net radiation based on the albedo, changed the value for soil surface conditions as growing stage of paddy rice, would be more important.
Estimated from the water budget and the potential evapotranspiration rate as paddy field in this area, daily rates of the net water requirement for the year 1994 were ranged between 6mm/d and 14.5mm/d, and indicated larger rates in the dry season from April to October than in the wet season from November to March.
In this study, the percolation loss was estimated in the verification paddy field from the water budget equation. At place where all terms of the water budget are not available, the value of percolation loss should be carefully decided based on the water supply from groundwater.抄録全体を表示PDF形式でダウンロード (997K) -
石郷岡 康史, 町村 尚, 楊 桂清1998 年 54 巻 2 号 p. 133-142
発行日: 1998/06/15
公開日: 2010/02/25
ジャーナル フリーDistribution of air temperature around Guyuan Prefecture, south part of Ningxia in China, which has only a few meteorological observation sites, was estimated in 2km×2km mesh size by using the following methods; 1) regression estimation by altitude of each mesh, 2) regression estimation by surface temperature estimated from GMS infrared data, 3) multiple regression estimation by topographical factors of each mesh, which were calculated using altitude mesh data around the study area, 4) multiple regression estimation by NDVI and altitude of each mesh.
Hourly air temperature was estimated by methods 1) and 2). Correlation coefficients by method 1) were low in winter morning, but were sufficiently high in other time. During the daytime, estimation by method 2) was accurate enough. But in most cases, accuracy of surface temperature method was lower than the method by using altitude, which was caused by low resolution of GMS data.
Monthly mean temperature and monthly mean maximum and minimum temperatures were estimated by methods 1), 3) and 4). Correlation coefficients by method 1) were low in winter, especially in monthly mean minimum temperature. For method 3), stepwise regression analysis was used to decide the most effective topographical factors for the monthly mean minimum temperature. As a result, some topographical factors except altitudes were selected in winter and estimation using selected topographical factors was more accurate than using altitude only. This result indicates that the effect of topographical factors for air temperature was larger than that of altitude in winter morning. For method 4), stepwise regression analysis was carried out and NDVI was selected for several months. Estimation using NDVI and altitude was more accurate than using only altitude. These results indicate that the condition of ground vegetation affect the air temperature distribution in summer.抄録全体を表示PDF形式でダウンロード (7869K) -
青野 靖之, 工藤 友美, 文字 信貴1998 年 54 巻 2 号 p. 143-154
発行日: 1998/06/15
公開日: 2010/02/25
ジャーナル フリーThe seasonal and spatial changes in heat budget terms in the forest in Mt. Ikoma area, located at the boundary of Osaka and Nara Prefectures, were estimated using LANDSAT/TM data, sensed in April, June, August and December. Sensible and latent heat fluxes were calculated using the bulk transfer equation for heat and for moisture, respectively. In the bulk equation for sensible heat transfer at each pixel, surface temperature (from TM band 6), air temperature (interpolated according to elevation) and wind speed (interpolated distribution using a variational method with consideration of complexity of the terrain) were used as variables. In the bulk equation for latent heat transfer, the moisture availability, wind speed, specific humidity of the air and saturation specific humidity at the surface temperature were used. The bulk transfer coefficient was corrected for diabatic conditions for each pixel. The moisture availability for each day was calculated, considering the normalized difference vegetation index (NDVI).
The distribution pattern of estimated sensible heat flux showed a strong contrast between the east and west sides of the ridge line. This contrast became stronger under strong wind conditions. In summer, the value of sensible heat flux was estimated as 160W m-2 under a calm condition, while it exceeded 200W m-2 in the case with more than 3m s-1 of mean wind speed. The estimations of latent heat flux fell within the range of 350 (summer)-100 W m-2 (winter). The moisture availability varied in the range of 0.15-0.53, according to wind speed and humidity. It was clear from this analysis that accurate interpolations of meteorological variables such as wind speed and air temperature distributions are important for deducing each heat flux, even with satellite-derived data.抄録全体を表示PDF形式でダウンロード (8892K) -
田中丸 重美, 竹花 稔彦, 木村 和義1998 年 54 巻 2 号 p. 155-160
発行日: 1998/06/15
公開日: 2010/02/25
ジャーナル フリー葉面の濡れやすさの異なる2種のオオムギ品種を用いて, 葉面の濡れ状態(葉面の水滴付着量, 水滴の接触角度)及び濡れ特性と葉面ワックスの関係について検討を行った。さらに降雨処理による濡れ特性の変化についても検討した。供試した材料として, 同質遺伝子系統で, 葉面の濡れやすさを除いては同じ遺伝的性質をもっているオオムギ「五畝四石埼1号」(正常葉系統)と「五畝四石埼1号変」(濡れ葉系統)の2系統を使用した。
第1葉(最上位葉)から第5葉(下位葉)の平均水滴付着量は, 正常葉系統では, 5.6mg/cm2, 濡れ葉系統では12.6mg/cm2であった。葉面の水滴接触角度は, 正常葉系統で125°, 濡れ葉系統93°であった。また葉面ワックス量は, 正常葉で17.3μg/cm2, 濡れ葉では9.3μg/cm2であった。
葉位別に水滴付着量, 接触角度を検討した結果, 両系統とも第2葉位がもっとも濡れにくく, 下位葉ほど付着量が多くなる傾向がみられた。水滴接触角は正常葉系統では葉位別差異は少なかったが, 濡れ葉では, 下位葉の角度は若い上位葉と比較して低い値であった。
両系統とも5時間の降雨処理により水滴付着量は増加する傾向がみられたが, 正常葉系統では増加が少なく, 濡れ葉系統では約40%の増加がみられた。また5日間の降雨処理により, 正常葉系統の接触角度はほとんど影響されなかったが, 濡れ葉系統では約30%の減少がみられた。また降雨処理により両系統ともワックス量の減少がみられた。正常葉系統では10-20%, 濡れ葉系統では第1葉で15%, 第2～3葉では約50%の減少がみられた。
以上のことから濡れ葉系統は正常葉系統と比較してワックス量が少なく, 雨水付着量が多く, 水滴接触角度が小さく, 濡れやすい性質をもっていることが明らかになった。また両系統とも活動の盛んな若い葉は濡れにくく, 葉齢の進んだ葉は濡れやすくなる傾向がみられた。さらに長時間降雨を受けると, 葉が濡れやすくなることを明らかにした。抄録全体を表示PDF形式でダウンロード (691K) -
毛 光伶, 蔵田 憲次1998 年 54 巻 2 号 p. 161-165
発行日: 1998/06/15
公開日: 2010/02/25
ジャーナル フリー結露によるべたがけ資材の間隙率と長波放射特性の変化を明らかにするため, 実用化している3種類の不織布を用いて, 結露した資材の間隙率の変化に関する実験を行った。実測値から間隙率と不織布単位面積当たりの結露量の回帰式を得た。その結果から, 結露した資材の長波放射特性の変化を計算した。結露によりべたがけ資材の放射率は最大で2倍になった。抄録全体を表示PDF形式でダウンロード (2072K) -
邱 国玉, 佐瀬 勘紀, 五十部 誠一郎, 奥島 里美1998 年 54 巻 2 号 p. 167-170
発行日: 1998/06/15
公開日: 2010/02/25
ジャーナル フリーPDF形式でダウンロード (2665K) -
植田 亨1998 年 54 巻 2 号 p. 171-177
発行日: 1998/06/15
公開日: 2010/02/25
ジャーナル フリーPDF形式でダウンロード (691K) -
気候変化影響研究部会解説清野 豁, 甲斐 啓子, 太田 俊二, 菅野 洋光, 山川 修治1998 年 54 巻 2 号 p. 179-186
発行日: 1998/06/15
公開日: 2010/02/25
ジャーナル フリーIn this paper, new knowledge of global warming is briefly described on the basis of the 1st and 2nd Working Group of IPCC (Intergovernmental Panel of Climate Change) published in 1996. The contents of this paper are arranged according to the oral reports in the 7th gathering of the Researching Group for Impacts of Climate Change (ICC) in the Society of Agricultural Meteorology of Japan on June 7, 1997. The main authors are as follows: Seino is §1 and §4, Kai in §2, Ohta in §3, Kanno and Yamakawa in §5. Observed climate change, its variability and uncertainty are discussed in §2. Assessment of impacts of climate change on terrestrial ecosystem is presented in §3. Agriculture under changing climate is introduced in §4. In §5, some problems as to the IPCC reports are mentioned including the discussions in the meeting.抄録全体を表示PDF形式でダウンロード (2510K) -
農業現場への応用を考えて耕地気象改善研究部会1998 年 54 巻 2 号 p. 187-190
発行日: 1998/06/15
公開日: 2010/02/25
ジャーナル フリーPDF形式でダウンロード (475K)
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